Electrical connectors have long been used to terminate and connect electrical cables having a plurality of insulated conductors in an outer insulative jacket. One use for such cable is to provide control signals to industrial and commercial machinery such as drill presses, lathes and the like. As these types of machinery rely upon the transmitted signals for proper functioning, the reliability of the connection between the signal source and the particular machine tool is essential.
Connectors typically used for such connections employ a multi-pin arrangement, where the individual electrical conductors are terminated with a pin-type terminal. The pins are then supported in pre-arranged and pre-configured openings in an insert. The insert is fixedly supported in one end of an elongate connector body. The opposite end of the connector body receives a sealing bushing and a gland nut to provide sealed termination of the cable.
As is typical with most sealing connectors, the sealing bushing is tightened around the cable jacket by attaching a gland nut to the end of the connector. Since the gland nut is screw-threaded progressively onto the connector, the frictional contact between the sealing bushing and the cable jacket has a tendency to twist the cable in the connector. This twisting motion of the cable within the connector may cause the individual conductors, held at the ends thereof in the insert, to helically twist. As the cable is held in fixed axial position in the connector by the sealing bushing and gland, one or more of the terminated pins may back out of the openings in the insert, making connection to that conductor unreliable. Thus the conductor would have to be re-terminated and the connection process begun anew.
While mechanical strain relief devices are known, which secure the terminated conductors in the insert, most are cumbersome to use and require additional parts and/or installation steps.